Sand blasting mechanism



Oct. 11,1938. A. J. PoNcELET SAND BLASTING MEGHANISM Filed June 24, 1955- ,b Vil?,

Patented Oct. 11, 1938 UNITED STATES .PATENT OFFICE Y 2,133,149 SAND BLASTING MECHANISM Arihu J. roncelei, Arlington, Calif. Application June 24, 1935, serial No. 28,171

5 Claims.

This invention relates to sand blasing mechanism.

An object of the invention is to provide a light weight mechanism of this character which can be conveniently carried in the hand of the user and wherein use is made of a pneumatic air gun through which a high velocity air stream can flow and the same be utilized to effect delivery into the stream of dry granular abrasive material from a container which is preferably, but not necessarily, carried by the gun.

A further object is to provide a sand blasting mechanism wherein means are employed to enable either an adm iXture of air and abrasive material or a mere high velocity air stream to be directed against a surface being treated as and when desired.

Among the many uses to which the invention can be put are the following, namely: (l) 'the removal or stripping of paint from metallic surfaces preparatory to soldering one surface to another; (2) the cleansing by sand blasting of any and all surfaces such as the spark plugs of internal combustion engines; (3) the etching of glass or metal by sand blasting; (4) the ornamentation of surfaces of wood with the use of stencils, etc.; and an important object of the invention is to provide mechanism characterized by an air gun, the nozzle of which is formed and disposed to enable the abrasive material to be eiectively directed in to more or less inaccessible crevices or spaces, the wall surfaces of which are to be cleaned or acted upon.

A further novel feature of the invention resides in the provision of means by which the abrasive material employed will move at a velocity which is low as compared with the Aintended high Velocity of an air stream, whereby to prevent undue wear upon the metallic surfaces of the conduit through which said material passes while in transit to the air stream in the discharge of the material from the mechanism by force of said air stream. A

Another object is to provide a sand blasting mechanism in which is embodied a novel form of container for the abrasive material, the same supported by and otherwise connected with the air gun of the mechanism whereby it can be removed and supplied with a charge'of said material and then quickly and conveniently reapplied to the gun for further use.

Other objects and advantages of the invention will be apparent from the following description, considered in conjunction with the accompanying drawing, in Which Figure .1' is a View partly in elevation and partly in longitudinal section of the device;

Figure 2 is a view in side elevation 'of the device; I

Figure 3 is a section on line3-3 of Figure 1; 5 Figure 4 is a section on line 4-4 of Figure 1. In carrying the invention into practice, use is made of a vertically disposed container 5, the neck 6 of which is provided with a threaded cap I which can be removed from the container as and when desired, so that the container can be supplied with a charge of suitable dry abrasive material, such as sand of required mesh.

Extending transversely across the crown. or closure wall of the cap 'I is a tubular conduit 8, l5 the same closed at one end by a removable screw plug 9 adjacent to which and formed in the walls of `the conduit is a small air intake orifice I0. Said conduit is provided with an intermediate partition II which subdivides the conduit into ductsIZ and I3, and, as'illustrated, a substantially U-shaped tube I4 is carried Aby the conduit and has its limb I5 in direct communication with the duct I2 of said conduit and its limb I6 in communication with the duct I3, whereby air entering the perforation I0 can continuously flow through the tube by suction induced at the discharge end I1 of said conduit. The return band I8 of the tube I4 has a small perforation I8a formed therein by means of which sand in the 30 container can be drawn into the tube by induced suction as the air ows through the tube as n aforestated and as clearly shown in Figure 3l of the drawing. Removably attached 'to the discharge end I1 of the conduit 8 lis an air gun I9, the same consisting of a barrel 20 having a hand grip 2| which is spaced apart laterally from the container to enable the grip to be grasped freely in the hand of the operator.

The barrel 20 is formed with an intake portway 22 and an outlet portway 23 and disposed between said portways is a valve seat 24 against which a disk valve 25 can close. Said valve is provided with a stem 26 which is yieldingly urged against a lifting lug 21 of a trigger 28 by means of a coil spring 29. The spring 29 is linterposed between the valve disk 25 and a spring' tensioning cap rBIJ, the-latter being removable from the barrelrand adapted to be manually adjusted to insure a firm closure of the valveagainst its coacting seat 24. `From the relationshipgto each other of the portways 22 and 23, it follows that when the disk 25 is lifted from its seat, air from a suitable'well-known pressure source can enter the portway 22 from an intake connection 3| and discharge into the portway 23 frombeneath Said disk.

Removably fitted to the forward end of the barrel 20 is a discharge nozzle 32 of hard metal, the inner end of the bore of which is formed with a flared portion 33. Ihreadedly tted to the barrel 2U and co-axially positioned in an enlarged bore 34 in the barrel is a short tubular hard metal member 35, the external diameter of which is less than the diameter of the bore 34. As shown in Figures 1 and 3, the discharge end I'I of conduit 8 communicates directly with theVY bore 34 through the'coupling device 36, whereby sand as it discharges from the duct I3 will be delivered to the bore 34. The forward end of the member 35 is provided with a tapered nose 3'I which extends into the ared portion of the bore of the nozzle 32, said nose being of a size to provide an annular space between same and the Walls of. said ared portion of the bore of said nozzle and being of a length to extend for- Wardly beyond the orice 36a in the coupling 36.

In operation, dry sand is placed in the container 5, and theV cap 'I securely sealed to the container. iWhen the container is in the position shown in Figure 1, the tube I4 penetrates the sand and the perforation I8a in the return bend I8 of the tube is disposed with respect to the bottom of the container to enable sand to be drawn into the tube by suction induced at the bore 34. Assuming the trigger 28 to be depressed and the valve disk 25 elevated above its seat 2.4, and assuming also that the connection 3| is in communication with a source of air pressure, it follows that an air stream at high velocity will discharge into the bore of the nozzle 32 from the member 35, thus inducing formation of suction at the discharge connection 3G of sufficient force to draw 'atmospheric air into the tube I4 by way of the perforation I and ,discharge same into the bore 34. In consequence thereof, sand will be drawn into the tube I4 by suction induced at the perforation Ia in said return bend I8, and same will be Vconducted to the bore of the nozzle 32 from which it can be directed against the surface to be acted upon.

By reason of the fact that the sand is drawn into the tube I4 by suction induced as aforestated, abrasion of the tube I4 andthe conduit 8 will be negligible, and these parts can, therefore, be made of light inexpensive metal. Due, however, to the high velocity'of the air stream passing through the barrel and nozzle 32 Vand through the bore of member 35, it is intended that these parts be constructed from hardened steel.

After a` surface has been sand blasted in the manner above described, the container 5 which is swiveled at the connection 36 may be inverted as shown in Figure 2, to -thus dispose the sand at a level beneath the perforation Ia in the return bend I8 of tube I4. The trigger 28 may now be actuated to open the valve 25 and permit a blast of air to be directed against the treated surface being acted upon, whereby to clean same of all loose ,particles of lsand and foreign matter.

. The` device vmay be of any suitable size to enable itto be conveniently held in the hand and the device freely manipulated. The container 5 may consist of a Mason fruitjar of a capacity to hold abouta pint of sand,` so-that the device when heldin the hand will be nicely balanced and of light weight. The nozzle 32 may be of any well-known form, :but is preferably of small external :diameter and is pointed at its outer end to enable it to be projected into more or less inaccessible spaces or crevices, such, for instance, as the space between the electrodes of a spark plug when the device is used to cleanse the electrodes.

What is claimed is:

1. In mechanism of the class described, a uid container having a removable cap; a substantially U-shaped tube carried by the cap and having an imperforate return bend disposed within the container and provided with. an intake orice through which fluid can pass to the tube from the container; a discharge nozzle; and means on the cap connecting the tube with the nozzle and having a duct open to the atmosphere and to one stretch of the aforestated tube by means of which air can be sucked into the intake orifice and fluid drawn into the tube to provide a 10W velocity iiuid stream, said means having a duct through which the low velocity fluidstream can pass to the nozzle; and means oy which a high velocity air streamv from a source of air under pressure can be discharged from the nozzle and along a line relative to the vsecond named duct, whereby to cause ejection at high velocity of the fluid stream from said nozzle, the rst said means having swivel connection with the nozzle such as will enable the container to be turned from a depending position relative to said means to a position thereabove, the aforementioned tube being of such length with respect to the depth of the container so that when the container is in the aforestated depending position, uid can be drawn into the tube as raforementioned for discharge at low velocity therefrom and whereby, when the container is turned to a position above said first means,l the discharge orice will be situated with respect to the level of fluid in the container to prevent entrance of fluid to the tube to permita high velocity air stream, devoid of uid, to pass from the nozzle from the aforestated pressure source. 'Y

2. A device of the class described comprising a nozzle from which air under pressure can discharge; a fluid container connected to swivel on the nozzle so as to be turned from a depending position to an inverted position; and a tube correlated with the nozzle and with the container and extending into the latter and provided with an ariiice into which fluid can enter the tube from the container by suction induced in the tube when air under pressure is discharging from the nozzle and the container is in a depending position, the length of thel tube being suchthat when the container is inverted, the orifice in the tube will be disposed above the level of fluid in the container to thus prevent entrance of fluid to the container Vwhen air under pressure is discharging from the nozzle.

3. A device of the class described comprising a fluid container; a nozzle' having a handle; means by which uid in the container can be ejectedl from the nozzle at high velocity; and means for mounting the container on the nozzle for swiveling movement relative thereto to compensate for angular movement of the nozzle in a vertical plane, so that the container can be disf posed in anupright position for the ejection of fluid therefromirrespective of the angle at which the nozzle is held. 1

4. A deviceof the class described comprising a fluid container; v.a nozzle having' a handle; means bywhich Yfluid in thercontainer can be ejected from-thenozzle at high velocity; means for mounting the container on the nozzle for swiveling movement relative thereto to compensate for angular movement of the nozzle in a vertical plane; the center of gravity of the container being below the mounting means, and the swiveling connection provided thereby being sufciently free for the container to maintain an upright position, irrespective of angular movement of the nozzle in a vertical plane.

5. A device of the class described comprising a fluid container; a nozzle having a handle; means by which iiuid in the container can be ejected from the nozzle at high velocity; means for mounting the container on the nozzle for swiveling movement relative thereto to compensate for angular movement of the nozzle in a vertical plane, so that the container can be disposed in an upright position for the ejection of fluid therefrom, irrespective of the angle at which the nozzle is held; and means by which iiuid is delivered to the nozzle from the container through said swivel mounting means, irrespective of the angular position of the nozzle relative to the container.

ARTHUR J. PONCELET. 

